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arXiv · 2606.11982

PAWS: Preference Learning with Advantage-Weighted Segments

Aleksandar Taranovic·Onur Celik·Niklas Freymuth·Ge Li·Serge Thilges·Huy Le·Tai Hoang·Rania Rayyes·Gerhard Neumann
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Abstract

Preference-based reinforcement learning (PbRL) learns policies from human trajectory-level comparisons, avoiding explicit reward design and expert demonstrations. Existing methods typically train utility functions on trajectory or segment-level preferences while relying on per-step utility estimates during policy optimization. This training and inference mismatch induces a distribution shift that severely degrades temporal credit assignment and limits policy learning. We analyze this issue and propose PAWS, a segment-based preference learning method that performs policy updates directly using segment-level advantage functions. By aligning utility training with policy optimization, PAWS preserves trajectory-level preference information and avoids unreliable per-step learning signals. Experiments on simulated robotic manipulation and locomotion tasks demonstrate that PAWS consistently outperforms existing PbRL approaches, highlighting the importance of distribution-consistent preference learning.

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Aleksandar Taranovic, Onur Celik, Niklas Freymuth, Ge Li, Serge Thilges, Huy Le, Tai Hoang, Rania Rayyes, Gerhard Neumann. 2026-06-10. PAWS: Preference Learning with Advantage-Weighted Segments. https://arxiv.org/abs/2606.11982

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